Human-powered treadle pumps, for example, pumps used to create suction or pressure to irrigate fields, exist in many forms. One type includes a pair of treadles connected to and disposed between a rocker and pistons. Each of the treadles is directly coupled to a corresponding piston. A tensile component (e.g., a rope or a chain) links together the rocker and the treadles and/or the rocker and the pistons. The rocker facilitates alternating, reciprocating movement of the treadles and the corresponding pistons. Downward movement of one treadle drives one piston downward, while upward movement of the other treadle lifts the other piston. Lifting a piston causes a suction movement to fill a piston cylinder with fluid. Depressing a piston pumps fluid out of the cylinder for use at a higher elevation or any other location.
Many existing human-powered treadle pumps mount the rocker on a tower or vertical shaft that extends above the treadles. This arrangement, however, can create instability and inefficiency in the operation of the pump. Adding stiffness to certain components to address instability and inefficiency may cause the overall weight to increase, as well as increase cost of the pump. Moreover, a heavier pump may still be inefficient, in that power transfer between components can be diminished due to relatively high friction losses and energy required to overcome inertial effects.